Uber will have to wait until spring 2018 at the very earliest to find out whether it will have its London license reinstated, a judge said on Monday.

The appeal case will be heard over the course of five days starting April 30, although it could possibly be delayed until June, Reuters reported the judge as saying in a preliminary hearing.

The ride-hailing service lost its license to operate in the British capital in September, when the city's transport regulator Transport for London (TfL) refused to issue a renewal. Uber immediately announced its intention to appeal TfL's decision, and the service is continuing to operate in London throughout the appeal process.

A week later, Uber CEO Dara Khosrowshahi paid London officials a visit and vowed to work with TfL to make sure the company's license is reinstated. The appeal was officially launched in mid-October.

The hearing on Monday will be followed by two more hearings later this week to decide whether a trade union and the London Taxi Drivers' Association can join TfL in its complaint against Uber.

"We filed our appeal so that we can continue serving millions of riders and tens of thousands of drivers in London," said an Uber spokeswoman in a statement. "However, we continue having constructive discussions with Transport for London in order to resolve this. As our new CEO Dara Khosrowshahi has said, we are determined to make things right."